Ext.define('MyApp.view.Viewport', {
    extend: 'Ext.container.Viewport',
    layout: 'border',
    items: [{
        region: 'north',
        xtype: 'appHeader'
    },{
        region: 'west',
        xtype: 'navigation',
        width: 250,
        minWidth: 200,
        split: true,
        stateful: true,
        stateId: 'mainnav.west',
        collapsible: true
    }, {
        region: 'center',
        layout:'fit',
        xtype: 'contentPanel'
    }]
});